JP2001094588A - Packet distribution system - Google Patents

Packet distribution system

Info

Publication number
JP2001094588A
JP2001094588A JP27176699A JP27176699A JP2001094588A JP 2001094588 A JP2001094588 A JP 2001094588A JP 27176699 A JP27176699 A JP 27176699A JP 27176699 A JP27176699 A JP 27176699A JP 2001094588 A JP2001094588 A JP 2001094588A
Authority
JP
Japan
Prior art keywords
receiving
packet
station
receiving station
stations
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP27176699A
Other languages
Japanese (ja)
Inventor
Koyo Ito
幸洋 伊藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Engineering Ltd
Original Assignee
NEC Engineering Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Engineering Ltd filed Critical NEC Engineering Ltd
Priority to JP27176699A priority Critical patent/JP2001094588A/en
Publication of JP2001094588A publication Critical patent/JP2001094588A/en
Withdrawn legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide a packet distribution system which performs reliable distribution even deterioration of a radio transmission line occurs as to radio communication using broadcasting communication. SOLUTION: A transmitting station 10 divides a data file into packets on a transmitting server 12 and distributes them to a plurality of receiving stations from a transmission device 11 through a ratio line 20. The receiving stations 21 to 23 receive the packets by using ratio communication line reception devices 31 to 33, decide an error or the absence of the received packets on receiving terminals 41 to 43, and send reception confirmation notice to a receiving station 22 of a previously selected master receiving station via a ground line. If received packets of the receiving stations 21 and 23 have an error or absence, the receiving stations 21 and 23 send an abnormality notice to the receiving station 22, which resends its the normal packet it has held to the receiving stations having given the abnormality notice. If reception abnormality of the same packet occurs at all receiving stations in a reception group 40, the receiving station 22 requests the transmitting station 10 to resend the packets.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は複数の受信局へ同報
通信するパケット配信システムに関し、特に受信異常の
受信局に対してパケットを再送する再送制御機能を有す
るパケット配信システムに関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet distribution system for broadcasting to a plurality of receiving stations, and more particularly to a packet distribution system having a retransmission control function for retransmitting a packet to a receiving station having abnormal reception.

【0002】[0002]

【従来の技術】従来、この種のパケット配信システムに
おいて配信されるパケットは、図3に示すように、一定
長に分割されたデータファイルにパケットヘッダを加え
て形成される。パケットヘッダ内は複数のフィールドで
構成され、伝送誤りを検出するフレームチェックシーケ
ンスFCSと、分割されたパケットの順番等を格納した
制御フィールドCを有している。受信局はこれらの情報
によって受信パケットの異常がないかを識別し、異常が
検出されると送信局に対してパケットの再送要求を行
う。
2. Description of the Related Art Conventionally, a packet distributed in this type of packet distribution system is formed by adding a packet header to a data file divided into a predetermined length as shown in FIG. The packet header is composed of a plurality of fields, and has a frame check sequence FCS for detecting a transmission error and a control field C storing the order of the divided packets and the like. The receiving station identifies whether there is any abnormality in the received packet based on the information, and when the abnormality is detected, requests the transmitting station to retransmit the packet.

【0003】従来のこの種のパケット配信システムが、
例えば、特開平10−200577号公報に記載されて
いる。図2は従来のパケット配信システムの構成を示す
ブロック図である。
A conventional packet distribution system of this kind is:
For example, it is described in JP-A-10-200577. FIG. 2 is a block diagram showing a configuration of a conventional packet distribution system.

【0004】図2に示されるように送信局100は、無
線回線400及び地上回線500を介して受信局20
0、300に接続されている。送信局100は無線回線
400を介して受信局200、300へパケットを同報
通信により配信する。受信局200、300では、受信
パケットの正誤判定を行い、例えばこの時、受信局20
0で受信パケットの誤りが検出された場合には、受信端
末220内の受信側再送要求部230が送信サーバ12
0内の送信側再送処理部130に対して再送要求通知を
送信する。再送要求を受信した送信局100は、無線回
線400を介して受信局200へ再送要求されたパケッ
トの再送信を行っている。
[0004] As shown in FIG. 2, a transmitting station 100 receives a signal from a receiving station 20 via a radio line 400 and a terrestrial line 500.
0,300. The transmitting station 100 distributes the packet to the receiving stations 200 and 300 by broadcast communication via the wireless line 400. The receiving stations 200 and 300 determine whether the received packet is correct or incorrect.
0 and an error in the received packet is detected, the receiving side retransmission request unit 230 in the receiving terminal 220
A retransmission request notification is transmitted to the transmitting side retransmission processing unit 130 within 0. The transmitting station 100 that has received the retransmission request is retransmitting the packet requested to be retransmitted to the receiving station 200 via the wireless line 400.

【0005】また複数の受信端末から同一パケットの再
送要求が発生した時に生じる再送信の繰り返しを防止す
るために、最初の再送要求から所用時間経過後に要求パ
ケット送信を行っている。
[0005] In order to prevent retransmission from being repeated when a plurality of receiving terminals request retransmission of the same packet, request packets are transmitted after a lapse of required time from the first retransmission request.

【0006】また、送信局側地上回線500の混雑を回
避するために、パケットの誤りおよび欠落のみを送信サ
ーバ120に送信している。
Further, in order to avoid congestion on the transmitting station side ground line 500, only errors and omissions of packets are transmitted to the transmitting server 120.

【0007】[0007]

【発明が解決しようとする課題】上述した従来のパケッ
ト配信システムでは、天候悪化等によって無線回線の劣
化または遮断が発生すると、受信局における受信パケッ
トの誤りまたは欠落が増加し、それに伴い送信局に対す
る再送要求の回数も増加する。そのため、多数の受信局
へ同報通信した時に上述のような現象が発生すると、送
信局に対する再送要求は更に増加してしまい、送信局の
負荷が増大してしまうという問題点があった。
In the above-described conventional packet distribution system, when the radio link is degraded or cut off due to bad weather or the like, errors or omissions of the received packet at the receiving station increase, and accordingly, the transmission station has a problem. The number of retransmission requests also increases. Therefore, if the above-described phenomenon occurs when broadcasting is performed to a large number of receiving stations, the number of retransmission requests to the transmitting station further increases, and there is a problem that the load on the transmitting station increases.

【0008】また従来技術ではパケットの再送信を無線
回線で行っているため、再び受信局で受信異常の発生す
る可能性が非常に高いという問題点があった。
[0008] Further, in the prior art, since retransmission of a packet is performed through a radio line, there is a problem that the possibility of occurrence of a reception error at a receiving station is very high again.

【0009】また従来技術では同一パケットに対する再
送を一回の同報通信によって再送信を行うために最初の
再送要求から所用時間経過後に要求パケットを送信して
いるが、多数の受信局が点在している等の理由で最初の
再送要求と最後の再送要求の到着時刻にずれが生じる
と、その効果を十分に発揮できないという問題があっ
た。
In the prior art, a request packet is transmitted after a required time elapses from the first retransmission request in order to perform retransmission of the same packet by one broadcast transmission. However, many receiving stations are scattered. If there is a difference between the arrival time of the first retransmission request and the arrival time of the last retransmission request for such reasons, there is a problem that the effect cannot be sufficiently exhibited.

【0010】本発明は上記問題点に鑑みてなされたもの
であって、多数の受信局への同一パケット配信時に、送
信側への再送要求回数を削減して送信局の負荷を軽減す
る一方、再送処理の信頼性を向上を図ることのできるパ
ケット配信システムを提供することを目的とする。
The present invention has been made in view of the above problems, and reduces the load on the transmitting station by reducing the number of retransmission requests to the transmitting side when the same packet is distributed to many receiving stations. An object of the present invention is to provide a packet distribution system capable of improving the reliability of retransmission processing.

【0011】[0011]

【課題を解決するための手段】請求項1記載の発明は、
パケット配信システムであって、送信局と複数の受信局
それぞれが無線回線及び地上回線を介して接続され、前
記送信局がファイルデータを分割して形成したパケット
を前記複数の受信局に対して前記無線通信回線を介して
同報通信するパケット配信システムにおいて、前記送信
局は、前記受信局のグループ化及び当該グループ内受信
局からマスタ受信局の選定後、当該グループ内受信局に
対し同一パケットを送信し、当該グループ内受信局は受
信パケットの正誤判定を行い、前記マスタ受信局の受信
パケット異常が検出された場合、前記マスタ受信局は当
該グループ内の他の受信局から正常パケットを受信し、
前記マスタ受信局以外の当該グループ内受信局の受信パ
ケット異常が検出された場合、当該受信局は前記マスタ
受信局に再送要求して正常パケットを受信し、当該グル
ープ内全ての受信局の受信パケット異常が検出された場
合、前記マスタ受信局は前記送信局に対して再送要求を
行い、前記送信局は当該グループ内全ての受信局に対し
てパケットの再送を行うことを特徴とする。
According to the first aspect of the present invention,
A packet distribution system, wherein a transmitting station and a plurality of receiving stations are connected via a radio line and a terrestrial line, and the transmitting station divides file data and forms a packet for the plurality of receiving stations. In a packet distribution system that broadcasts via a wireless communication line, the transmitting station, after grouping the receiving stations and selecting a master receiving station from the receiving stations in the group, sends the same packet to the receiving stations in the group. Transmit, the receiving stations in the group perform correct / incorrect determination of the received packet, and when an abnormality of the received packet of the master receiving station is detected, the master receiving station receives a normal packet from another receiving station in the group. ,
When a reception packet abnormality of a receiving station in the group other than the master receiving station is detected, the receiving station requests a retransmission to the master receiving station, receives a normal packet, and receives packets of all receiving stations in the group. When an abnormality is detected, the master receiving station issues a retransmission request to the transmitting station, and the transmitting station retransmits a packet to all receiving stations in the group.

【0012】請求項2記載の発明は、前記マスタ受信局
は地上回線を介して他の受信局へパケットを再送するこ
とを特徴とする。
The invention according to claim 2 is characterized in that the master receiving station retransmits a packet to another receiving station via a terrestrial line.

【0013】請求項3記載の発明は、前記送信局は、少
なくとも2つのグループのマスタ受信局から同一パケッ
トの再送要求がされた場合には全てのグループのマスタ
受信局から応答を受信した後にパケットの再送を行うこ
とを特徴とする。
According to a third aspect of the present invention, when the transmitting station requests retransmission of the same packet from at least two groups of master receiving stations, the transmitting station receives packets from all groups of master receiving stations after receiving a response. Is retransmitted.

【0014】そして請求項1記載の発明によれば、受信
局をグループ化してマスタ受信局がグループ内の他の受
信局に対してパケットの再送を行っているため、送信局
への再送要求を削減できる。またマスタ受信局の受信パ
ケット異常が検出された場合、マスタ受信局はグループ
内の他の受信局から正常パケットを受信しているため、
マスタ受信局では高い確率で正常パケットを保有するこ
とができる。
According to the first aspect of the present invention, the receiving stations are grouped and the master receiving station retransmits the packet to the other receiving stations in the group. Can be reduced. In addition, when an error in the received packet of the master receiving station is detected, the master receiving station receives a normal packet from another receiving station in the group.
The master receiving station can hold a normal packet with a high probability.

【0015】請求項2記載の発明によれば、マスタ受信
局からグループ内の他の受信局へのパケットの再送が地
上回線を介して行われるため、再送パケットの誤りや欠
落が発生する確率を極めて低くすることができる。
According to the second aspect of the present invention, since the retransmission of a packet from the master receiving station to another receiving station in the group is performed via the terrestrial line, the probability of occurrence of an error or loss of the retransmitted packet is reduced. It can be very low.

【0016】請求項3記載の発明によれば、前記送信局
は少なくとも2つのグループのマスタ受信局から同一パ
ケットの再送要求がされた場合には全てのグループのマ
スタ受信局から応答を受信した後にパケットの再送を行
うため、複数のグループに対する同一パケットの再送を
削減することができる。
According to the third aspect of the present invention, when at least two groups of master receiving stations request retransmission of the same packet, the transmitting station receives responses from the master receiving stations of all groups. Since packet retransmission is performed, retransmission of the same packet to a plurality of groups can be reduced.

【0017】[0017]

【発明の実施の形態】次に、本発明にかかるパケット配
信システムの一実施形態について図面を参照して詳細に
説明する。図1は本発明にかかるパケット配信システム
の一実施形態の構成を示すブロック図であり、無線回線
20及び地上回線30を介して送信局10に受信局21
〜23が接続されている。また図示していないが、送信
局10にはこの他にも複数の受信局が接続されている。
Next, an embodiment of a packet distribution system according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of a packet distribution system according to the present invention, in which a transmitting station 10 is connected to a receiving station 21 via a radio line 20 and a terrestrial line 30.
To 23 are connected. Although not shown, a plurality of other receiving stations are connected to the transmitting station 10.

【0018】送信局10は、送信サーバ12と、送信装
置11とを備えている。送信サーバ12は、保有するデ
ータファイルを分割してパケットを生成し、送信装置1
1に出力する。また送信サーバ12は、パケットの送信
に先立って受信局のグループ化及び当該グループ内の受
信局からマスタ受信局の選定を行う。更に送信サーバ1
2は、受信局からの再送要求に応じてパケットの再送処
理を行う送信側再送処理部121を有している。
The transmitting station 10 includes a transmitting server 12 and a transmitting device 11. The transmission server 12 divides the held data file to generate a packet, and
Output to 1. Further, the transmission server 12 performs grouping of the receiving stations and selects a master receiving station from the receiving stations in the group before transmitting the packet. Further, transmission server 1
2 has a transmission side retransmission processing unit 121 that performs a packet retransmission process in response to a retransmission request from a receiving station.

【0019】受信局21〜23は、無線通信回線用受信
装置31〜33と、受信端末41〜43とを備えてい
る。無線通信回線受信装置31〜33は、送信装置11
から送信されたパケットを無線回線20を介して受信す
る。受信端末41〜43は無線通信回線用受信装置31
〜33から受信したパケットのデータファイル変換及び
正誤判定を行う。
The receiving stations 21 to 23 are provided with radio communication line receiving devices 31 to 33 and receiving terminals 41 to 43. The wireless communication line receiving devices 31 to 33 are connected to the transmitting device 11.
Are received via the wireless line 20. The receiving terminals 41 to 43 are the receiving device 31 for the wireless communication line.
The data file conversion and correct / false judgment of the packets received from # 33 are performed.

【0020】受信端末41〜43は、受信パケットの誤
りを検出すると後述するグループ内マスタ受信局または
送信局10にパケットの再送を要求する地上回線用送受
信部411、422、433を有している。また地上回
線用送受信部411、422、433は、図1には示さ
れていないが、地上回線によって互いに接続される一
方、送信局10の送信側再送処理部121にも地上回線
によって接続されている。なお、図示されていない受信
局に関しても、受信局41〜43と同様な構成を備えて
いる。
Receiving terminals 41 to 43 have terrestrial line transmitting / receiving sections 411, 422, and 433 which request the in-group master receiving station or transmitting station 10 to retransmit the packet upon detecting an error in the received packet. . Although not shown in FIG. 1, the terrestrial transmission / reception units 411, 422, and 433 are connected to each other by a terrestrial line, and are also connected to the transmission side retransmission processing unit 121 of the transmitting station 10 by the terrestrial line. I have. Note that the receiving stations not shown have the same configuration as the receiving stations 41 to 43.

【0021】次に送信局10があるユーザグループに対
して同報通信を行う時の動作について図1を参照して詳
細に説明する。送信局10は、同報通信に先立って、送
信サーバ12で受信局のグループ分け及びマスタ受信局
の選定を行う。各受信局には予めID番号が付与されて
おり、送信局10はこのID番号を用いてグループ分け
及びマスタ受信局の選定を行う。
Next, the operation when the transmitting station 10 performs broadcast communication with a certain user group will be described in detail with reference to FIG. The transmitting station 10 performs grouping of receiving stations and selection of a master receiving station in the transmitting server 12 prior to broadcast. Each receiving station is assigned an ID number in advance, and the transmitting station 10 performs grouping and selection of a master receiving station using the ID number.

【0022】グループ分け及びマスタ受信局の選定が完
了すると送信局10は、パケット配信を行う前に、グル
ープ内に所属する受信局のID番号とマスタ受信局とな
る受信局を指定するID番号を含むグループ情報を全受
信局へ送信する。各受信局は全受信局の情報を予め保有
しており、この保有情報と受信したグループ情報から自
分自身の所属するグループ及びそのマスタ受信局を認識
する。本実施形態では図1に示す通り、受信局22をマ
スタ受信局とし、受信局21、23をスレーブ受信局と
して受信局グループ40が構成されると仮定する。
When the grouping and the selection of the master receiving station are completed, the transmitting station 10 transmits the ID number of the receiving station belonging to the group and the ID number designating the receiving station to be the master receiving station before performing packet distribution. The group information including the group information is transmitted to all receiving stations. Each receiving station has information on all the receiving stations in advance, and recognizes the group to which it belongs and its master receiving station from the held information and the received group information. In this embodiment, as shown in FIG. 1, it is assumed that the receiving station 22 is a master receiving station, and the receiving stations 21 and 23 are slave receiving stations to form a receiving station group 40.

【0023】グループ内の受信局21〜23は地上回線
30を介して情報の送受信が可能である。またマスタ受
信局である受信局22の地上回線用送受信部422は、
送信局10の送信側再送処理部121と地上回線30を
介して情報の送受信が可能である。
The receiving stations 21 to 23 in the group can transmit and receive information via the ground line 30. Also, the transmission / reception unit 422 for the terrestrial line of the receiving station 22 which is the master receiving station,
Information can be transmitted and received to and from the transmission side retransmission processing unit 121 of the transmission station 10 via the ground line 30.

【0024】次に送信局10はパケット配信を行う。送
信局10はパケット配信する時に配信対象となる受信局
グループ40を指定してパケットを送信する。これによ
り指定された受信局グループ40だけがパケット受信可
能となり、対象外の受信グループ(図示せず)ではパケ
ットを受信できなくなる。
Next, the transmitting station 10 performs packet distribution. When transmitting a packet, the transmitting station 10 specifies a receiving station group 40 to be distributed and transmits the packet. As a result, only the designated receiving station group 40 can receive packets, and cannot receive packets in receiving groups (not shown) that are not targeted.

【0025】パケットを受信した受信局21〜23は受
信端末41〜43で受信パケットの正誤判定を行い、ス
レーブ受信局である受信局21、23は受信パケットが
正常であれば受信確認通知を、異常であれば異常通知を
受信局22へ地上回線30を介して送信する。
Receiving stations 21 to 23 which have received the packet make correct / incorrect judgment of the received packet at receiving terminals 41 to 43, and receiving stations 21 and 23 which are slave receiving stations receive a reception confirmation notice if the received packet is normal. If abnormal, an abnormal notification is transmitted to the receiving station 22 via the ground line 30.

【0026】例えば受信局21で受信したパケットに異
常が検出されると、受信局21は地上回線用送受信部4
11から地上回線30を介して受信局22へ異常通知を
送信する。受信局22は受信局21から異常通知を受信
すると、自局が保有する正常パケットを受信局21へ地
上回線30を介して再送する。
For example, when an abnormality is detected in the packet received by the receiving station 21, the receiving station 21
An error notification is transmitted from 11 to the receiving station 22 via the ground line 30. Receiving the abnormality notification from the receiving station 21, the receiving station 22 retransmits the normal packet held by the own station to the receiving station 21 via the ground line 30.

【0027】またマスタ受信局である受信局22は自局
の異常パケット受信を検出すると、グループ内の受信確
認通知を送信してきた受信局21または23から地上回
線30を介して正常パケットを受信する。そうすること
で受信局22は非常に高い確率で正常パケットを保有す
ることができる。これら一連の処理によって受信局22
は、自局を含むグループ内全ての受信局21〜23でパ
ケットを正常に受信されたことを確認すると、送信局1
0に対してその旨を通知する。
When the receiving station 22, which is the master receiving station, detects the reception of an abnormal packet of the own station, the receiving station 22 receives a normal packet from the receiving station 21 or 23 which has transmitted the reception confirmation notification within the group via the ground line 30. . By doing so, the receiving station 22 can hold a normal packet with a very high probability. The receiving station 22
Confirms that the packets have been normally received by all the receiving stations 21 to 23 in the group including the own station.
0 is notified.

【0028】次にグループ内全ての受信局がパケット受
信異常と判定した時の動作を説明する。受信局グループ
40内の全ての受信局において受信パケットの誤りや欠
落等の受信異常が検出された場合、受信局22は地上回
線30を介して送信局10の送信側再送処理部121へ
パケットの再送要求を行う。再送要求を受信した送信局
10は、送信側再送処理部121で再送処理を行い、送
信装置11から無線回線20を介して同報通信により受
信局へパケットを再送する。この時、送信局10は受信
グループを指定しているので、再送要求をしていないグ
ループが改めてパケットを受信することはない。
Next, the operation when all the receiving stations in the group determine that the packet reception is abnormal will be described. When a reception error such as an error or loss of a received packet is detected in all the receiving stations in the receiving station group 40, the receiving station 22 sends the packet to the transmitting side retransmission processing unit 121 of the transmitting station 10 via the terrestrial line 30. Request retransmission. The transmitting station 10 that has received the retransmission request performs retransmission processing in the transmitting side retransmission processing unit 121, and retransmits the packet from the transmitting device 11 to the receiving station by broadcast communication via the wireless line 20. At this time, since the transmitting station 10 has designated the receiving group, the group that has not requested retransmission does not receive the packet again.

【0029】また、二つ以上のグループが同一のパケッ
トを再送要求した場合には、同一のパケットが送信局1
0から二度再送信されることを防止するために、全ての
受信局グループからパケットの受信情報を受信した後に
再送信を行う。
When two or more groups request retransmission of the same packet, the same packet is
In order to prevent retransmission from 0 twice, retransmission is performed after receiving the reception information of the packet from all the receiving station groups.

【0030】ここで、全受信局数M、受信局グループ数
N(但し、1≦N≦(M/2))として、受信局側から
送信局へのアクセス数Aを示す。 A=N/M ・・・・・ (1)
Here, the number A of accesses from the receiving station to the transmitting station is shown as the number of all receiving stations M and the number of receiving station groups N (where 1 ≦ N ≦ (M / 2)). A = N / M (1)

【0031】上記式(1)より、受信局グループ40は
2つ以上の複数の受信局から構成されているため、受信
局側からの送信局へのアクセス数Aは従来の半分以下に
なることがわかる。この結果、送信局の負担は確実に軽
減されることがわかる。
According to the above equation (1), since the receiving station group 40 is composed of two or more receiving stations, the number of accesses A from the receiving station to the transmitting station should be less than half the conventional number. I understand. As a result, it can be seen that the burden on the transmitting station is reliably reduced.

【0032】また、各受信局グループ数内の受信局数を
K、従来技術における1つの受信局からの再送要求確率
をQ1(0≦Q1≦1)とすると、本発明のマスタ受信
局である受信局22からの再送要求確率Q2は次のよう
になる。 Q2=Q1×K ・・・・・ (2) 但し、K>1
If the number of receiving stations in each receiving station group number is K and the probability of retransmission request from one receiving station in the prior art is Q1 (0 ≦ Q1 ≦ 1), the receiving station is the master receiving station of the present invention. The retransmission request probability Q2 from the receiving station 22 is as follows. Q2 = Q1 × K (2) where K> 1

【0033】この結果、各グループ内の受信局数が全て
Kであるとすると、本発明における全体からの再送要求
確率Qは次のようになる。 Q=N×Q1×K ・・・・・ (3)
As a result, assuming that the number of receiving stations in each group is all K, the overall retransmission request probability Q in the present invention is as follows. Q = N × Q1 × K (3)

【0034】また、従来技術における受信局全体の再送
要求確率Q3は次のようになる。 Q3=M×Q1 ・・・・・ (4)
The retransmission request probability Q3 of the entire receiving station in the prior art is as follows. Q3 = M × Q1 (4)

【0035】式(3)と式(4)から従来技術と本発明
の比をとると次のようになる。 Q/Q3=(N/M)×Q1(K−1) ・・・・・ (5)
From the equations (3) and (4), the ratio between the prior art and the present invention is as follows. Q / Q3 = (N / M) × Q1 (K−1) (5)

【0036】この式(5)に示される通り、再送要求確
率は、各受信局単体で再送要求を行うよりも、本発明の
ように受信局をグループ化した時の方が減少することが
わかる。
As shown in equation (5), the retransmission request probability is smaller when the receiving stations are grouped as in the present invention than when the retransmission request is made by each receiving station alone. .

【0037】[0037]

【発明の効果】請求項1記載の発明によれば、複数の受
信局をグループ化し、更にグループ内にマスタ受信局を
設けてグループ内の他の受信局の管理を行うため、送信
側への再送要求を削減することができ、送信局の負荷を
軽減することができる。
According to the first aspect of the present invention, a plurality of receiving stations are grouped, and a master receiving station is provided in the group to manage other receiving stations in the group. Retransmission requests can be reduced, and the load on the transmitting station can be reduced.

【0038】請求項2記載の発明によれば、再送パケッ
トの誤りまたは欠落を削減することができ、再送処理の
信頼性を向上することができる。
According to the second aspect of the present invention, it is possible to reduce errors or omissions in retransmission packets, and to improve the reliability of retransmission processing.

【0039】請求項3記載の発明によれば、複数のグル
ープに対する同一パケットの再送を削減することがで
き、送信局の負荷を更に軽減することができる。
According to the third aspect of the present invention, retransmission of the same packet to a plurality of groups can be reduced, and the load on the transmitting station can be further reduced.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明にかかるパケット配信システムの一実施
形態の構成を示すブロック図である。
FIG. 1 is a block diagram showing a configuration of an embodiment of a packet distribution system according to the present invention.

【図2】従来のパケット配信システムの構成を示すブロ
ック図である。
FIG. 2 is a block diagram showing a configuration of a conventional packet distribution system.

【図3】データファイルのパケット化の概要及びパケッ
ト構成を示す説明図である。
FIG. 3 is an explanatory diagram showing an outline of packetization of a data file and a packet configuration.

【符号の説明】[Explanation of symbols]

10,100 送信局 11,110 送信装置 12,120 送信サーバ 121,130 送信側再送処理部 20,400 無線回線 21〜23,200,300 受信局 30,500 地上回線 31〜33 無線通信回線用受信装置 40 受信局グループ 41〜43,220,320 受信端末 230,330 受信側再送要求部 411,422,433 地上回線用送受信部 10, 100 transmitting station 11, 110 transmitting device 12, 120 transmitting server 121, 130 transmitting side retransmission processing unit 20, 400 wireless line 21 to 23, 200, 300 receiving station 30, 500 terrestrial line 31 to 33 wireless communication line receiving Device 40 Receiving station group 41 to 43, 220, 320 Receiving terminal 230, 330 Receiving side retransmission request unit 411, 422, 433 Terrestrial line transmitting / receiving unit

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 送信局と複数の受信局それぞれが無線回
線及び地上回線を介して接続され、前記送信局がファイ
ルデータを分割して形成したパケットを前記複数の受信
局に対して前記無線回線を介して同報通信するパケット
配信システムにおいて、 前記送信局は、前記受信局のグループ化及び当該グルー
プ内受信局からマスタ受信局の選定後、当該グループ内
受信局に対し同一パケットを送信し、当該グループ内受
信局は受信パケットの正誤判定を行い、 前記マスタ受信局の受信パケット異常が検出された場
合、前記マスタ受信局は当該グループ内の他の受信局か
ら正常パケットを受信し、 前記マスタ受信局以外の当該グループ内受信局の受信パ
ケット異常が検出された場合、当該受信局は前記マスタ
受信局に再送要求して正常パケットを受信し、 当該グループ内全ての受信局の受信パケット異常が検出
された場合、前記マスタ受信局は前記送信局に対して再
送要求を行い、前記送信局は当該グループ内全ての受信
局に対してパケットの再送を行うことを特徴とするパケ
ット配信システム。
1. A transmitting station and a plurality of receiving stations are respectively connected via a radio line and a terrestrial line, and a packet formed by dividing the file data by the transmitting station is transmitted to the plurality of receiving stations by the radio line. In a packet distribution system that broadcasts through, the transmitting station, after grouping the receiving stations and selecting a master receiving station from the receiving stations in the group, transmits the same packet to the receiving stations in the group, The receiving station in the group makes a right / wrong determination of the received packet, and when an error in the received packet of the master receiving station is detected, the master receiving station receives a normal packet from another receiving station in the group, and If an abnormal reception packet is detected for a receiving station in the group other than the receiving station, the receiving station requests a retransmission to the master receiving station and receives a normal packet. When the reception packet abnormality of all the receiving stations in the group is detected, the master receiving station issues a retransmission request to the transmitting station, and the transmitting station issues a retransmission request to all the receiving stations in the group. A packet distribution system for retransmitting a packet.
【請求項2】 前記マスタ受信局は地上回線を介して他
の受信局へパケットを再送することを特徴とする請求項
1記載のパケット配信システム。
2. The packet distribution system according to claim 1, wherein said master receiving station retransmits a packet to another receiving station via a terrestrial line.
【請求項3】 前記送信局は、少なくとも2つのグルー
プのマスタ受信局から同一パケットの再送要求がされた
場合には全てのグループのマスタ受信局から応答を受信
した後にパケットの再送を行うことを特徴とする請求項
1または請求項2記載のパケット配信システム。
3. The transmitting station, when receiving a request for retransmission of the same packet from at least two groups of master receiving stations, performs retransmission of the packet after receiving responses from the master receiving stations of all groups. Claims characterized
The packet distribution system according to claim 1 or 2.
JP27176699A 1999-09-27 1999-09-27 Packet distribution system Withdrawn JP2001094588A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP27176699A JP2001094588A (en) 1999-09-27 1999-09-27 Packet distribution system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP27176699A JP2001094588A (en) 1999-09-27 1999-09-27 Packet distribution system

Publications (1)

Publication Number Publication Date
JP2001094588A true JP2001094588A (en) 2001-04-06

Family

ID=17504554

Family Applications (1)

Application Number Title Priority Date Filing Date
JP27176699A Withdrawn JP2001094588A (en) 1999-09-27 1999-09-27 Packet distribution system

Country Status (1)

Country Link
JP (1) JP2001094588A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008198047A (en) * 2007-02-15 2008-08-28 Brother Ind Ltd Information distribution system, information distribution method, distribution unit, node unit, etc
JP2014511646A (en) * 2011-03-07 2014-05-15 インテル コーポレイション Grouped inter-machine communication
JP2014192843A (en) * 2013-03-28 2014-10-06 Hitachi Kokusai Electric Inc Communication system
JP2019146032A (en) * 2018-02-21 2019-08-29 パナソニックIpマネジメント株式会社 Radio communication system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008198047A (en) * 2007-02-15 2008-08-28 Brother Ind Ltd Information distribution system, information distribution method, distribution unit, node unit, etc
JP2014511646A (en) * 2011-03-07 2014-05-15 インテル コーポレイション Grouped inter-machine communication
JP2014192843A (en) * 2013-03-28 2014-10-06 Hitachi Kokusai Electric Inc Communication system
JP2019146032A (en) * 2018-02-21 2019-08-29 パナソニックIpマネジメント株式会社 Radio communication system
JP7117494B2 (en) 2018-02-21 2022-08-15 パナソニックIpマネジメント株式会社 wireless communication system

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